import java.util.Scanner;

public class StringOj {
    public static boolean isChar(char ch){
        //判断字符是否为英文和数字
        if((ch >= 'a' && ch <= 'z') ||(ch >= '0' && ch <= '9'))
            return true;
        return false;
    }
    //判断字符串是否的回文
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        int right = str.length() - 1;
        int left = 0;
        //对前后字符进行比较
        while(left < right){
            char chR = str.charAt(right);
            char chL = str.charAt(left);
            if(isChar(chR) && isChar(chL)){
                if(chR == chL){
                    right--;
                    left++;
                }else {
                    System.out.println("该字符串不是回文");
                    return;
                }
            }
        }
        System.out.println("该字符串是回文");
    }

    //最后一个单词的长度
    public static void main2(String[] args) {
        String str = "loveu loveu Osborn!";
        String []ret = str.split(" ");
        System.out.println(ret[ret.length-1].length());
    }
    //第一个只出现一次的字符
    public static void main1(String[] args) {
        String str  = "abudabss";
        int len = str.length();
        int [] count = new int[26];
        // 将字符串对应下标的字符出现的次数存入数组中
        for(int i = 0; i < len; i++){
            count[str.charAt(i)-'a'] ++;
        }
        // 按字符串顺序判断字符出现的次数
        int i = 0;
        while(str.charAt(i) != '\0'){
            if(count[str.charAt(i) - 'a'] == 1){
                System.out.println(str.charAt(i));
                break;
            }
            i++;
        }
    }
}

